• Alpha 5
  • Alpha 4
  • Alpha 3




The asset Alpha 5 is located on the even land.
Oil presence was found in the deposits comprising units: B1, B2 and B3.
Reservoir layers of the productive formation mainly consist of organic limestones.
The asset was brought into commercial production in 1999.
Currently, 40 wells have been drilled at this field.
Given that the existing aquifer is not really active, it was decided to start a pressure maintenance system in 2000. Event thought the cumulative voidage replacement ratio is 120%, the reservoir pressure in some areas is still quite low and continues to decline. The redevelopment program of this asset aims to increase the current development parameters.

Production history

Abbreviation Value Unit of measurement Description
1 Current Oil Recovery Factor 0.18 unit fraction Current Oil Recovery Factor
2 Current Voidage Replacement Ratio 1.5 unit fraction Current Voidage Replacement Ratio
3 ∑ Qo 5.05 mil. m3 Cumulative oil production
4 ∑ Qw 6.1 mil. m3 Cumulative water production
5 ∑ Qwi 14 mil. m3 Cumulative water production
6 mil. m3 1.2 unit fraction Cumulative voidage replacement ratio
7 Yw 78 % Watercut

Field summary data

Abbreviation Value Unit of measurement Description
1 Ztop -1600 m Mean true vertical depth (bottom part of unit B1)
2 ZOWC -1660 / -1670 / -1680 m Oil-water contact (unit B1 / unit B2 / unit B3)
3 H 91 m Average total reservoir thickness
4 Heff 20 m Average effective reservoir thickness
5 Hpay 18.5 m Average effective oil-saturated thickness
6 Ti 45 C Initial reservoir temperature
7 Pi 16,400 kPa Initial pressure at oil-water contact
8 Φ 0.14 unit fraction Average porosity
9 cr 4*10-7 1/kPa Rock compressibility
10 kh 53 mD Average horizontal permeability
11 kv/kh 0.1 unit fraction Vertical reservoir heterogeneity
12 krow/μo 0.3 1/cP Maximum relative permeability to oil/oil viscosity
13 krwo/μw 0.3 1/cP Maximum relative permeability to oil/oil viscosity
14 swi 0.3 unit fraction Initial water saturation
15 sor 0.28 unit fraction Residual oil saturation
16 STOIIP 27.2 mil. m3 Initial oil in place
17 ES @ ultimate 0.86 unit fraction Target sweep efficiency
18 unit fraction 0.5 unit fraction Target oil recovery factor




The asset Alpha 4 is located on the even land.
Oil presence was found in the deposits comprising units: B1, B2 and B3.
Reservoir layers of the productive formation mainly consist of organic limestones.
The asset was brought into commercial production in 1999.
The first producer that was put into operation was well E5, and it had a high watercut as a result of water breakthrough.
Therefore, to avoid such situation in future, the production levels of the remaining producers were limited. Currently, 39 wells have been drilled at this field.
The pressure at this field is poor, and is only maintained through the water-bearing edgewater, this is why in 1991 it was decided to start pressure maintenance. Event thought the cumulative voidage replacement ratio is 131%, the reservoir pressure in some areas is still quite low and continues to decline.
The redevelopment plan aims to restore 2 million m3 of oil over the next 5 years to achieve the originally planned indicators.

Production history

Abbreviation Value Unit of measurement Description
1 Current Oil Recovery Factor 0.21 unit fraction Current Oil Recovery Factor
2 Current Voidage Replacement Ratio 1.6 unit fraction Current Voidage Replacement Ratio
3 ∑ Qo 6.8 mil. m3 Cumulative oil production
4 ∑ Qw 7.6 mil. m3 Cumulative water production
5 ∑ Qwi 19.8 mil. m3 Cumulative water production
6 mil. m3 1.3 unit fraction Cumulative voidage replacement ratio
7 Yw 76 % Watercut

Field summary data

Abbreviation Value Unit of measurement Description
1 Ztop -1560 m Mean true vertical depth (bottom part of unit B1)
2 ZOWC -1550 / -1590 / -1610 m Oil-water contact (unit B1 / unit B2 / unit B3)  
3 H 90 m Average total reservoir thickness
4 Heff 38 m Average effective reservoir thickness
5 Hpay 24 m Average effective oil-saturated thickness
6 Ti 45 C Initial reservoir temperature
7 Pi 15.500 kPa Initial pressure at oil-water contact
8 Φ 0.16 unit fraction Average porosity
9 cr 5*10-7 1/kPa Rock compressibility
10 kh 45 mD Average horizontal permeability
11 kv/kh 0.1 unit fraction Vertical reservoir heterogeneity
12 krow/μo 0.17 1/cP Maximum relative permeability to oil/oil viscosity
13 krwo/μw 0.3 1/cP Maximum relative permeability to oil/oil viscosity
14 swi 0.3 unit fraction Initial water saturation
15 sor 0.28 unit fraction Residual oil saturation
16 STOIIP 32 mil. m3 Initial oil in place
17 ES @ ultimate 0.83 unit fraction Target sweep efficiency
18 unit fraction 0.5 unit fraction Target oil recovery factor


The Alpha 3 oil deposit is part of a giant oilfield located on the even land.
Oil presence was found in the deposits comprising units: A2, A3 and A4.
Reservoir layers of the productive formation mainly consist of organic limestones.
The asset was brought into commercial production in 1993.
The first producer that was put into operation was well E3, and it had a high watercut as a result of water breakthrough.
Therefore, to avoid such situation in future, the production levels of the remaining producers were limited.
Currently, 39 wells have been drilled at Alpha 3.
Aquifer was not active enough, this is why in 1996 it was decided to start pressure maintenance.
Event thought the cumulative voidage replacement ratio is 110%, the reservoir pressure in some areas is still quite low and continues to decline.
A field gathering system is present at the field. The current oil throughput available at the Alpha 3 is 600 m3/day, the liquid throughput is 800 m3/day. However, there is still a way to upgrade the field gathering system.
The pressure maintenance consists of the following elements: water intake, lift station and valve manifold. The water intake provides the lift station with 700 m3 of water per day, moreover the bottom water also feeds the lift station. A lift station has a pump with a maximum throughput of 1100 m3/day and a pressure of 100 bar. The pressure maintenance has the potential for improvement.

Production history

Abbreviation Value Unit of measurement Description
1 Current Oil Recovery Factor 0.24 unit fraction Current Oil Recovery Factor
2 Current Voidage Replacement Ratio 1.2 unit fraction Current Voidage Replacement Ratio
3 ∑ Qo 1.8 mil. m3 Cumulative oil production
4 ∑ Qw 0.6 mil. m3 Cumulative water production
5 ∑ Qwi 2.8 mil. m3 Cumulative water injection
6 ∑ VRR 1.1 unit fraction Cumulative voidage replacement ratio
7 Yw 52 % Watercut

Field summary data

Abbreviation Value Unit of measurement Description
1 Ztop -1261 m Mean true vertical depth (bottom part of unit B1)
2 ZOWC -1257 / -1260 m Oil-water contact (unit A2 / units A3+A4)
3 H 30.1 m Average total reservoir thickness
4 Heff 11.7 m Average effective reservoir thickness
5 Hpay 11 m Average effective oil-saturated thickness
6 Ti 32 C Initial reservoir temperature
7 Pi 12.500 kPa Initial pressure at oil-water contact
8 Φ 0.18 unit fraction Average porosity
9 cr 5*10-7 1/kPa Rock compressibility
10 kh 24.3 mD Average horizontal permeability
11 kv/kh 0.1 unit fraction Vertical reservoir heterogeneity
12 krow/μo 0.2 1/cP Maximum relative permeability to oil/oil viscosity
13 krwo/μw 0.6 1/cP Maximum relative permeability to oil/oil viscosity
14 swi 0.2 unit fraction Initial water saturation
15 sor 0.2 unit fraction Residual oil saturation
16 STOIIP 7.8 mil. m3 Initial oil in place
17 ES @ ultimate 0.76 unit fraction Target sweep efficiency
18 unit fraction 0.57 unit fraction Target oil recovery factor
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